1. Technical Field
The present invention generally is related to the field of osteal guides, surgical drilling systems and methods and devices for drilling osteal tunnels, and more particularly is related to methods for drilling angled osteal tunnels.
2. Related Art
The anterior and posterior cruciate ligaments in the knee assist in providing stability to the function of the knee. The cruciate ligaments control gliding, sliding, and rotation of the knee. To accomplish this, the anterior and posterior cruciate ligaments function according to the principles of a crossed four bar linkage, which is closely related to and dependent upon the bony constraints of the surrounding bones. Thus, the anatomic origin and insertion of both of the ligaments is crucial. Often the anterior cruciate ligament (ACL) becomes ruptured or torn, requiring replacement and reconstruction of the ligament in order to restore normal usage of the knee. When the ACL is restored or replaced, the ACL or a substitute synthetic or harvested graft must be reattached to the bone. The ACL graft is anchored in place either inside or outside of osteal tunnels or passages formed in the tibia or femur. It is preferential to locate and drill the tunnels at precise locations so the ACL will be reattached at the natural location or so the graft will be implanted in the optimum position. If a ligament reconstruction is performed in the appropriate location, then normal motion and stability can be restored. Otherwise, the ligament will eventually be too loose or too tight for normal function.
Similarly, tissue repair to the shoulder area, such as reattaching torn rotator cuff tendons to bone, also can be accomplished through open surgery or arthroscopic surgery. Because open surgery introduces potential problems with the trauma associated with the large area of skin, muscle and tissue that must be incised to perform such surgery, arthroscopic surgery is preferred because it has the advantages of requiring only a small incision, thus reducing the risk of infection, blood loss and the like sometimes caused by open surgery. The rotator cuff can be reattached to the humerus by suturing the tendon to the bone by passing the suture through a transosteal tunnel drilled through the proximal portion of the humerus. The location at which the tunnel is to be drilled is paramount because the axillary nerve, a major nerve which innervates the deltoid muscle, lies close to the preferred reattachment site. Movement of the shoulder may be impaired if the axillary nerve is damaged. Often, this results in a tunnel being close to the surface of the bone, which tunnel may have a thin wall and therefore be relatively weak and subject to breaking.
The repair of torn ligaments by anchoring them into an osteal tunnel created within the affected bone is dependent upon complex interdependencies between the ligaments of a human body. Not only must an osteal tunnel be created so as to provide optimal positioning and tension, but avoidance of major nerves, blood vessels, and other anatomical obstructions also dictate the positioning of the tunnels. Further, while it may be desirable for surgeons to employ their discretion in selecting the entrance site of the osteal tunnel, limitations in visibility and accuracy considerations dictate that surgical positioning instruments are needed to ensure that an osteal tunnel has a precise drill exit point. Often, surgeons are required to work in an area that is “boxed in” by nerves, which gives rise to a need for surgeons to forego the use of conventional surgical positioning instruments that might interfere with these delicate areas.
There are several limitations to current techniques of fixing soft tissue to bone. The primary methods can be divided into two categories, the implementation of bone tunnels or the use of fixation devices such as suture anchors. The latter carries the risk of implant complications including infection and bony osteolysis in addition to failure of fixation. Transosseous tunnels are a more attractive option. Current transosseous tunnel techniques can be divided into two types. The first involves the creation of a straight tunnel using guides placed on the surface of the bone and drilling from one point to the other. The second involves the creation of curved tunnels using drilling or awling devices that begin at both entry point of the tunnel and meet in the middle. However, these techniques are limited by technical constraints including the size of the bony bridge, surgical exposure required to allow for access to the bone, and anatomical constraints such as nerve and vessel proximity. As such, these limitations further limit the use of transosseous techniques in the setting of arthroscopic surgery, especially in the shoulder. This is because such this type of surgery is performed through limited exposure and is technically constrained by anatomic landmarks.
Surgical drill guides for use in drilling precision transosteal tunnels through bone are known in the art. For example, U.S. Pat. Nos. 5,163,940, 5,330,468 and 6,120,511 all disclose surgical drill guides. Drill guide devices, such as those taught in the above-referenced patents, generally comprise a housing having an axial opening, a probe connected to the housing and having a tip that is adapted to be disposed within the interior of the joint at the distal point where one end of the tunnel is to exit the target bone, and a guide wire sleeve for directing a guide wire into position on the surface of one of the bones of the joint. The housing is connected to the probe by an adjustable rack that is generally of a circular arc configuration. The housing is arranged so that its axial opening is more or less aligned to intersect with the aforementioned probe tip, and the guide wire sleeve is generally slidable or variable in position within the housing's axial opening. The relative angular position of the probe and the guide wire sleeve contained within the housing is slidably adjustable on the rack in order to accommodate differently sized human bones and joints. All of the aforementioned parts are held in relation to one another by releasable locking means known in the art.
The guide wire sleeve is positioned such that a guide wire can be inserted into the bone in order to properly position a drill. Once the guide wire is inserted, the sleeve is removed from the guide wire, leaving the guide wire embedded in the bone. A cannulated drill bit is then positioned about the guide wire and a straight hole is drilled to the exit point initially marked by the tip of the probe. A suture is then affixed to, through, or around the torn ligament, and the suture or both are drawn into the osteal tunnel by a needle eye or alligator clamp that is run through either the sleeve, the osteal tunnel, or both. The suture is then tied in a knot, stapled to the bone, or the instrument used to pull the suture through the osteal tunnel remains in the tunnel as an anchor which must later be removed from the bone.
In use, the drill guide device tip is placed at the desired exit point of the tunnel and the guide wire sleeve is positioned at the desired entry point of the tunnel. A drill bit is inserted through the guide wire sleeve and a tunnel is drilled through the bone from the guide wire sleeve (entry point) to the tip (exit point). Generally, the tunnel is a straight bore in the form of a hypotenuse across the corner of the bone. With smaller bones, this tunnel can be very close to the surface of the bone, and therefore the tunnel wall closest to the surface of the bone can be thin and weak.
Each of the disclosed prior art guides are for performing straight transosteal tunneling, which can result in a weakening of the bone, especially when the tunnel created is close to the bone surface, or the guides require entry or exit points for the tunnel which are difficult to access. Further, prior art guides do not allow for flexibility in the positioning on the entrance point of the osteal tunnel, which is desirable when a surgeon meets with biological obstacles such as nerves or blood vessels. Also, many different and complex instruments are required to perform the completed surgery, which makes the surgery more difficult and susceptible to error. Finally, prior art methods of attaching the suture to or within the bone often require either a complex procedure to secure the suture, or a second surgery to remove an embedded anchoring device.
Accordingly, there is a need for an improved osteal guide, more particularly an osteal guide with improved stability and performance, resulting in improved tunnel strength. There is also a need for an improved method for drilling osteal tunnels, more particularly angled osteal tunnels, which allows a surgeon to be both flexible and accurate in the placement of the osteal tunnels. Further, there is a need for improved osteal guide components that simplify surgery while maintaining accuracy. Finally, there is a need for an improved device for securing or anchoring sutures used in ligament reconstruction. It is to these and other needs that the present invention is directed.